I just recently purchased this antenna, I built it per the supplied manual, the Maco V58 corrected manual and using all of the information I found on its construction out there on the web I can find. It just does not work for me as advertised.
I tested the antenna at three heights above ground, 6.5', 16.5' and 22'. I have tried two different lengths of coax, the VNA launch cable all with the same results. The antenna center frequency as built, is between 22-23 MHz.
The Workman manual states, the radiator length starting point at 240, the Maco is 248". I set the bracket that is clamped to the radiator to a point that allows one inch of vertical clearance between the tuning ring ends.
I have tried the Master Chief instructions, as well as doing the math. Nothing adds up....to a 5/8.
The way I interpret the antenna, is the ring is a 1 turn inductor, tapped 6.25" from the center connection point of the two halves. This makes the lumped loading side of the inductor 24", the tap wander lead is 9.5" and the angle bracket is 7", for a total of 40.5". The shunt side of the inductor is 11.5" at the suggested starting point.
The math suggests, this should work at 248" in total length (less the base tube at 12", fr a total radiator of 236
") but it doesn't. So, I am thinking the ring match is not working as intended and is being cancelled. The only way I can find a match at 27 MHz, is at around 16', or actually slightly less. This leads me to believe that this antenna is a 1/2 wavelength antenna. To get to 5/8 wavelength, one would need to increase the length.
This antenna has been built by others that experience the same results that I have. The manufacturer has not been helpful. Maco says this antenna is a copy of theirs, that has some build problem and does not work. I have read quite a bit about the Maco, but the Workman info is sparse. I am looking for some real world experience that may shed some light on this, as I have wasted 4 days doing this and that to make this thing work on 27 MHz as a 5/8 wave, to no avail.
Thanks,
SL
I tested the antenna at three heights above ground, 6.5', 16.5' and 22'. I have tried two different lengths of coax, the VNA launch cable all with the same results. The antenna center frequency as built, is between 22-23 MHz.
The Workman manual states, the radiator length starting point at 240, the Maco is 248". I set the bracket that is clamped to the radiator to a point that allows one inch of vertical clearance between the tuning ring ends.
I have tried the Master Chief instructions, as well as doing the math. Nothing adds up....to a 5/8.
The way I interpret the antenna, is the ring is a 1 turn inductor, tapped 6.25" from the center connection point of the two halves. This makes the lumped loading side of the inductor 24", the tap wander lead is 9.5" and the angle bracket is 7", for a total of 40.5". The shunt side of the inductor is 11.5" at the suggested starting point.
The math suggests, this should work at 248" in total length (less the base tube at 12", fr a total radiator of 236
") but it doesn't. So, I am thinking the ring match is not working as intended and is being cancelled. The only way I can find a match at 27 MHz, is at around 16', or actually slightly less. This leads me to believe that this antenna is a 1/2 wavelength antenna. To get to 5/8 wavelength, one would need to increase the length.
This antenna has been built by others that experience the same results that I have. The manufacturer has not been helpful. Maco says this antenna is a copy of theirs, that has some build problem and does not work. I have read quite a bit about the Maco, but the Workman info is sparse. I am looking for some real world experience that may shed some light on this, as I have wasted 4 days doing this and that to make this thing work on 27 MHz as a 5/8 wave, to no avail.
Thanks,
SL